Environmental Effects Of Animals In South Africa

1. Introduction

The introduction of plant species by humans increased during the last five centuries, especially during the twentieth century, due to rapid increase in trade and travel across the globe (Dogra et al., 2010). Human activities are the primary cause of intentional or unintentional introduction and invasion of species (Vila and Pujadas, 2001). Most of the plants that have been introduced perform the purpose for which they are intended and therefore benefit humans in multiple ways (McNeely, 2001). Species introductions, therefore, are an essential part of human welfare and local cultures in virtually all parts of the world (McNeely, 2001).
South Africa is a biodiversity rich country, ranks as the third most biologically diverse

Most early assessments of the impacts of alien plants in South Africa concentrated on the environmental impacts, particularly the impacts on biodiversity (Van wilgen et al., 2001). The emphasis of this assessment was on mapping species believed to use more water than native vegetation, so succulent (e.g. Cactaceae), herbaceous (e.g. grasses, annuals) and aquatic invaders were generally excluded (Van wilgen et al., 2001).
Most alien grasses found in South Africa are known to be invasive in other parts of the world, but their South African environmental statuses are unknown. The lack of information limits the management actions for controlling these grasses. Conservation managers need to know what grass invasions are doing to indigenous plant and animal species, how current grazing and fire management affects their abundance, and how to and whether to control grasses in natural vegetation and as part of rehabilitation management (Milton, 2004). Although, Not every alien species turns out to be invasive (Hertling and Lubke, 2000), naturalized alien grasses that are invasive are not listed in the NEM:BA categories due to information

Hence the need of risk assessment, that will provide a comprehensive review of the breadth and depth of impacts and possible invasion by the introduced grass species. The results of this research could be used to influence management priorities of alien grasses in South Africa.
1.2 Aim and objectives:

The aim of the project is to investigate and to determine the environmental and socio-economic impact of introduced grasses that have naturalized in South Africa.

The aim will be achieved through the following objectives: • By identifying the introduced grasses currently found in South Africa.
• Assessing the alien grasses’ possible risk in South Africa through literature (in comparison to their impact in other countries).
• Investigating the current distribution and the abundance of the introduced grasses in the country (which includes their conservation status, Invasive status, Geographic extent, and Potential future distribution).
• Exploring some management options available to control invasive grasses.
• Determining the category of some alien grasses, according to the National Environmental Management: Biodiversity Act (NEM: BA).

1.3 Research questions
- What are the alien grasses found in South Africa?
- What is the impact of the introduced grasses